From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_HIGH,USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2BE5DC04AAD for ; Tue, 7 May 2019 17:18:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E83352087F for ; Tue, 7 May 2019 17:18:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557249490; bh=xt9ukkJvDmf42/+1FX7EomlPuDAXRZaZI20EEYYs5jM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=vaJSXChIs/2M0cALOpYyVRoq8Ollq7uaTPdFeskPCYbhrfXVdaOq0PHMjq0Mm39/w BIB8eu/BhaSaM6lV2mzlbhpzaKYpoAZqHdTxFyV4xV43fqMI9mrJtSpwFJIf3XVk+z zgBEHu9Ii8GCDaFRXkxI8nAvfv07i5GLqUXPRlyI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727256AbfEGRSJ (ORCPT ); Tue, 7 May 2019 13:18:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:36078 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726144AbfEGRSI (ORCPT ); Tue, 7 May 2019 13:18:08 -0400 Received: from localhost (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BEFAB206A3; Tue, 7 May 2019 17:18:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557249488; bh=xt9ukkJvDmf42/+1FX7EomlPuDAXRZaZI20EEYYs5jM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=P13JV0rmV+5jHlhlN519NNBjhELHn7/LNhU9HK1HfT551G7PtkVA1vPvH2NhGGovl iugCemv8wI3IXV48UKY55GgEdHi8U98lXAlBJmVdJj7X9uwf6oOshqmXdQw6+mYpFP HToXiAVL+O2CLBxNhwDl2wZ+Ki/mNA2aVcJX1aoI= Date: Tue, 7 May 2019 13:18:06 -0400 From: Sasha Levin To: Linus Torvalds Cc: Alexander Duyck , LKML , stable , Mikhail Zaslonko , Gerald Schaefer , Michal Hocko , Michal Hocko , Mikhail Gavrilov , Dave Hansen , Alexander Duyck , Pasha Tatashin , Martin Schwidefsky , Heiko Carstens , Andrew Morton , Sasha Levin , linux-mm Subject: Re: [PATCH AUTOSEL 4.14 62/95] mm, memory_hotplug: initialize struct pages for the full memory section Message-ID: <20190507171806.GG1747@sasha-vm> References: <20190507053826.31622-1-sashal@kernel.org> <20190507053826.31622-62-sashal@kernel.org> <20190507170208.GF1747@sasha-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 07, 2019 at 10:15:19AM -0700, Linus Torvalds wrote: >On Tue, May 7, 2019 at 10:02 AM Sasha Levin wrote: >> >> I got it wrong then. I'll fix it up and get efad4e475c31 in instead. > >Careful. That one had a bug too, and we have 891cb2a72d82 ("mm, >memory_hotplug: fix off-by-one in is_pageblock_removable"). > >All of these were *horribly* and subtly buggy, and might be >intertwined with other issues. And only trigger on a few specific >machines where the memory map layout is just right to trigger some >special case or other, and you have just the right config. > >It might be best to verify with Michal Hocko. Michal? Michal, is there a testcase I can plug into kselftests to make sure we got this right (and don't regress)? We care a lot about memory hotplug working right. -- Thanks, Sasha